1. Field of the Invention
The invention generally relates to power-driven conveyors, and particularly to drag or slide conveyors in which the conveyor belt is an assemblage of end-linked, segmented belt elements assembled by connectably mating integral flanged surfaces of the respective elements.
2. Background of the Invention
Conveyor belts adapted to move along curved paths are disclosed in U.S. Pat. No. 2,701,050 to Steinborn, in U.S. Pat. No. 2,836,283 to Horth, in U.S. Pat. No. 3,169,631 to Knappe, among others, culminating in U.S. Pat. Nos. 4,144,965, 4,438,842, and 4,937,006 to Alldredge et al. for assemblies for such conveyors. These patents disclose a novel flexible conveyor belt, sometimes known as a Serpentix belt, which name is derived from the U.S. manufacturer and trademark owner, Serpentix Conveyor Corporation of Westminster, Colo.
The Serpentix belt is capable of traveling in a laterally curved path, which may include horizontal curves, vertical curves, and complex curves with serpentine or helical portions. With the development of this type of conveyor belt, it became possible to install a single conveyor that negotiates omni-directional corners, in contrast to the prior art practice of requiring load transfer between intersecting linear conveyor paths. As a result, loads could be conveyed through complex work areas or building structures on a single conveyor, without the needless expense, spillage and loss of floor area associated with use of a transfer station.
Known conveyor belts that are capable of traveling in a curved path are assemblages of convoluted, modular elements typically fabricated of rubber or, optionally, a synthetic material. A belt formed of such modular elements, which also are referred to as belt pan units, may have a troughed structure. Relative to the longitudinal centerline of typical belt movement, both lateral sides of the belt may angle upwardly to cradle the load toward the centerline of the belt. In addition, the belt forms a series of longitudinally spaced transverse convolutions or raised folds. The convolutions enable the belt to bend laterally, such as through lateral corners, while traveling longitudinally. In addition, the convolutions aid in retaining the load at a fixed longitudinal position on the belt. Consequently, such a belt, i.e., a Serpentix belt, is well suited for use with loose or granular loads because it retains such loads despite vertical, horizontal, and complex helical bends in the conveyor path. The modular elements or belt pan units are assembled by attachments to form an endless belt. This type of conveyor has applications, for example, in mining, quarrying, and manufacturing operations to transport bulk materials. Linked together, the assembled elements form a loop that is flexible in three dimensions.
The modular elements are assembled at unions by mating connections along integral end-oriented flanges. Periodically one union among a sequential plurality of unions between modular elements in a belt is mounted to a transverse support, such as an arm, to support the conveyor belt. The support arms are attached to a pulling means such as a drag chain. The support arms can be attached to carriages, for example having lateral wheels or rollers that ride on shaped rails, or having centrally attached sliding or rolling stabilizer elements riding in a stabilization channel. Rails and central channels can be fabricated both along straight runs and through curves that define a closed path for a belt conveyor extending in any relative direction.
An assembled conveyor belt is defined by an alternating series of convolutions and pan areas. A single modular element or belt pan unit typically will be of sufficient length to include at least one convolution. At least one-half of a pan area extends from each opposite longitudinal face of the convolution. The modular element typically will be longitudinally symmetrical, allowing insertion into the length of a conveyor belt in either of two directional orientations. At both end edges of the pan areas of a belt pan unit, the modular element includes a depending, transverse stiffener, which typically is a metal or plastic flange structure extending across the width of the belt pan unit and shaped in a troughed profile matching the upward angle of the belt sides.
A modular element optionally may include a plurality of convolutions and thus define one complete pan area between each pair of included convolutions. In addition, a pan half-portion completes each longitudinal end of the modular element. If a convolution should become damaged or torn, the damaged belt pan can be replaced individually. A belt pan carrying only a single convolution is efficient and economical to replace. However, an offsetting consideration is that the entire conveyor belt initially must be assembled of the individual belt pans, which requires a maximum assembly task when the belt pans are each of minimum length.
Typically, the modular elements are joined together, including the periodic attachments of the support arms, using sets of bolts with nuts and washers. These fasteners are applied through boltways in the juxtaposed end stiffeners of sequential belt pans. A sufficient number and suitable spacing of such fasteners is employed to draw together the juxtaposed stiffeners in order to close the abutment line between joined edges of sequential belt pans. The fasteners may encounter unusually high opposing forces in a laterally bendable belt when the belt turns a corner. Yet, belt pans should be held together with minimal separation at the pan junctions so that the load is retained from loss through the junctions.
Similarly, foreign matter should be kept out of the junctions to prevent wear and to better enable cleaning the belt. To augment the compression between flanges achieved with bolt sets, the resilient material of the belt pan unit may extend beyond the end face of the associated stiffeners by a small dimension. These extensions are compressed when juxtaposed stiffeners of sequential belt pan units are bolted together to form the belt. The compressed resilient extensions provide a seal between sequential belt pan units. However, for purposes of assembly and maintenance, the provisioning and physical manipulation of bolting for the belt assemblages is labor-intensive, and therefore time consuming and costly.
It would be desirable to provide an improved method and apparatus to simplify provisioning and greatly reduce time for assembly and disassembly of conveyor belts formed of modular elements.
The United States patents cited above are hereby incorporated herein by reference in their entirety. To inventor's knowledge, others have not practiced the inventive method and apparatus.
To achieve the foregoing and other objects and in accordance with the purpose of the present invention, as embodied and broadly described herein, the clip, assemblage, and method of this invention may comprise the following.